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Environment & Energy

wtmusic

(39,166 posts)

13. "Desert refrigerators" have been around for millennia

Reply to OKIsItJustMe (Original post)

Wed Mar 27, 2013, 09:39 PM

Mar 2013

"Nocturnal ice making

In India before the invention of artificial refrigeration technology, ice making by nocturnal cooling was common. The apparatus consisted of a shallow ceramic tray with a thin layer of water, placed outdoors with a clear exposure to the night sky. The bottom and sides were insulated with a thick layer of hay. On a clear night the water would lose heat by radiation upwards. Provided the air was calm and not too far above freezing, heat gain from the surrounding air by convection would be low enough to allow the water to freeze by dawn."

http://en.wikipedia.org/wiki/Radiative_cooling

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New Type of Solar Structure Cools Buildings in Full Sunlight [View all] OKIsItJustMe Mar 2013 OP

I wish people overall prized and honored high levels of intelligence, knowledge and creativity. Kurovski Mar 2013 #1

The article on the Stanford.edu site doesn't seem very clear, at least to me. drm604 Mar 2013 #2

It seems to reflect the energ rather than destroy or create it. Gore1FL Mar 2013 #3

It actually does more than that (in theory at least) OKIsItJustMe Mar 2013 #6

Thanks!! n/t Gore1FL Mar 2013 #9

As someone said,"There is no free lunch" TexasProgresive Mar 2013 #5

“How do the panels transmit radiant heat to space?” OKIsItJustMe Mar 2013 #7

Intuitively, I think these new surfaces are reflecting radiation at higher frequencies... NYC_SKP Mar 2013 #14

(In theory) they would do more than that OKIsItJustMe Mar 2013 #15

"Thanks smart folks" Voice for Peace Mar 2013 #4

The way it's described is a bit confusing caraher Mar 2013 #8

But the article says that it cools during the day. drm604 Mar 2013 #10

Yes caraher Mar 2013 #11

And radiation is a 4th power of Temp. So it could be very effective. Gregorian Mar 2013 #12

"Desert refrigerators" have been around for millennia wtmusic Mar 2013 #13

I'm impressed IrishAyes Mar 2013 #19

If you swap out your Vic be sure to get a gazebo wtmusic Mar 2013 #22

Yeah, I wouldn't know how to keep busy w/o rehab IrishAyes Mar 2013 #23

Doesn't explain how the building's heat would reach the panels Progressive dog Mar 2013 #16

Try this Google search OKIsItJustMe Mar 2013 #17

Thanks IrishAyes Mar 2013 #24

I hope IrishAyes Mar 2013 #18

I rather doubt it will OKIsItJustMe Mar 2013 #20

Probably won't happen in my lifetime IrishAyes Mar 2013 #21

fascinating! I missed this, thought others might have too. so kicked. recommended! Bill USA Jan 2014 #25

Awesome SamKnause Jan 2014 #26